152 
The Food of Birds. 
neutral elements we find a sprinkling of ants (two per 
cent.), larvae of a Tenebrionid ( Merancantha contracta*) 
four per cent., and thousand-legs (Iulidae) one per cent. 
Long strips of grass, in pieces much too large to have 
been eaten by any of the insects present, were found in 
the stomachs of two of these birds, and also occurred 
during each of the three following months. I am in doubt 
whether these were taken as food ; but, since I have found 
them in no other bird, and since a species which feeds so 
largely on cutworms and grasshoppers may have ac- 
quired the power of digesting the very considerable 
quantities of grass contained in the intestines of these 
insects, I have thought it best to include them in the per- 
centages of food. It is probable, however, that they were 
swallowed accidentally with insects taken from the 
ground. 
It will be noticed that the excess of Coleoptera in 
April is largely compensated by the diminished quanti- 
ties of Orthoptera and caterpillars. 
May. 
In this month nine birds were taken, from six localities 
in central and northern Illinois, in 1876-80. The Lepi- 
doptera, Coleoptera and Orthoptera return to about their 
normal ratios, but spiders rise to the excessive figure of 
twenty-one per cent. This ratio is, however, partly mis- 
leading, as, although six of the nine birds had eaten spi- 
ders, yet eleven per cent is due to a single bird, which 
had eaten nothing else. In such a case a larger number 
of specimens is required to restore the balance, so vio- 
lently disturbed. Two birds of this month had eaten 
moths, and five had eaten cutworms. The averages stand 
fifty-five per cent, of moths, caterpillars, dune-beetles, 
curculios and Orthoptera, opposed to thirty-five per cent, 
of Carabidse, soldier-bugs and spiders. The Carabidae in- 
clude- Cratacanthus dubius, Agonoderus comma , Aniso- 
dactylus, and Harpalus. Other details may be obtained 
from the table at the close of this paper. 
* For the determination of this species and most of the other larvae 
which have been identified specifically, I am under obligations to Professor 
Riley. 
